It has been a problem for persons, who cannot see well enough to read the graduations marked on a syringe or to read the labels of a bottle, to load the syringe with the proper dosage of the ingredients of one or more bottles. For example, in loading a springe with the proper dosage of two bottles for an injection of insulin for the treatment of diabetes, the conventional procedure for a person who can see well is to withdraw the plunger of a syringe to the proper graduation for the required total dosage of the ingredients of two bottles, insert the needle of the syringe into the first bottle and press the syringe plunger forwardly to a selected graduation marked on the syringe to insert an amount of air into the bottle equal to the proper dosage of that bottle's ingredients, withdraw the needle from that bottle, insert the needle into a second bottle and push the plunger forwardly as far as it will go to inject into the second bottle an amount of air equal to the doage desired from the second bottle, withdraw the syringe plunger to the graduation mark on the syringe barrel which loads the syringe with the proper dosage of the ingredients of the second bottle, withdraw the syringe and its needle from the second bottle, insert the needle into the first bottle, and withdraw the plunger to the desired graduation mark on the syringe barrel to load the syringe with the proper dosage of the ingredients of the first bottle, whereby the total dosage of ingredients from the first and second bottle is the correct dosage.
However, if the operator or person loading the syringe cannot see well enough to read the graduation markings on the syringe, he cannot load the syringe with the proper dosage.